Conventional and widely-employed blowing agents for expanded plastic(s) production are either organic materials, such as azodicarbonamide and the like or equivalent, which are inherently relatively costly and/or fluorocarbon and the like or equivalent physical blowing agent materials which are suspect as being environmentally deleterious.
Ammonium nitrate (NH.sub.4 NO.sub.3) is known to be thermally decomposable into gaseous products; but its action is sluggish and, per se, unsuited and dissatisfactory for direct, straightforward use as a blowing agent for the manufacture of plastic foam or expanded products.
Nothing in prior art appears to realistically concern itself with nor teach or lead to an effective, efficient and extremely reliable means and technique for utilizing ammonium nitrate as a blowing agent in and for plastics compositions in the manner of composition and beneficial functionality and operability following the way so crucially indigenous as in the present contribution to the art.